FISHES FROM NORTHEASTERN PACIFIC — CHAPMAN 507 



free lobe is proportionately large. The pectorals are inserted low 

 and have broad and nearly vertical bases. The rays reach a vertical 

 from the ventral when depressed. The ventrals are inserted under 

 the tliird or fourth ray of the dorsal. The caudal rays extend ante- 

 riorly along the caudal peduncle until there is only a shght space left 

 between them and the adipose above and the anal below. 



Remarks. — The only species in the genus with which this form could 

 be confused is Bathylagus milleri Jordan and Gilbert (Jordan and 

 Evermann, 1896-1900, p. 2825). In the original description of 

 that species, based on a single badly mutilated specimen, the dorsal 

 rays are given as 8 and the anal rays as 24, both of which are within 

 the range of B. alascanus. However, it was stated that the origin 

 of the dorsal is nearer the base of the caudal than the tip of the snout. 

 Out of 28 specimens of B. alascanus 18 specimens have the origin of the 

 dorsal nearer the tip of the snout than the base of the caudal, 6 have it 

 equidistant between them, and 4 have the origin of the dorsal closer 

 to the base of the caudal. It is also stated that in B. milleri "the 

 interorbital space is converted into a very deep channel by two verti- 

 cal thin lamellae which arise on either side and mark off the narrow 

 interorbital space from the contiguous supraocular areas." In 5. 

 alascanus the interorbital is only moderately concave. In fact, in the 

 smaller specimens, such as that from station 1116B, the interorbital 

 space is fiat, sloping forward. The concavity of the large specimens 

 is caused by the expansion dorsally of the large eyes. In B. milleri 

 the occipital region is swollen and prominent, much higher tlian the 

 interorbital space. In B. alascanus the occiput is normal, and slopes 

 gradually to the interorbital space. In view of these differences, the 

 sketchy description of B. milleri, the badly mutilated condition of the 

 type specimen of that species, and the striking differences of B. alas- 

 canus from the other species in the genus, it is described as new. 



The locations of the stations at which this fonn was taken show a 

 range for B. alascanus extending from off Cape St. James (southern 

 tip of Queen Charlotte Islands) throughout the Gulf of Alaska to 

 south of the Shumagin Islands. All the specimens except tliree were 

 taken outside the 100-fathom line. These three, at stations 218C, 

 338B, and 407B, were taken on the edge of the 100-fathom line. 

 None of the specimens taken in the standard hauls was taken in the 

 "A" nets, 12 were taken in "B" nets, 17 were caught in the "C" 

 nets. Only one specimen (from station 391D) was taken in a surface 

 net. These data would indicate a bathypelagic habitat, outside the 

 edge of the continental shelf, as normal for this species. 



Named in reference to its habitat, the Gulf of Alaska. 



